The vector used to transmit a gene segment is a

Plasmid

Explanation:

A plasmid is a small-molecule of DNA that can replicate independently in the cell. They are present in bacteria ( some archea) but its does not have the essential information of the bacteria for life. Plasmids usually carry ganes that benefit the bacteria like antibiotic-resistant genes that can be transferred to one bacteria to another.  

In molecular biology, plasmids, artificially constructed, are used as vectors to transfer a specific characteristic to another cell. They are usually used to express particular genes of interest, like the gene that codifies insulin is transferred in a plasmid to a bacterial cell, to produce insulin for farmaceutical industries.

desert perennials often survive by remaining dormant during dry periods of the year, then springing to life when water becomes available. most annual desert plants germinate only after heavy seasonal rain, then complete their reproductive cycle very quickly.